1. Technical Field
The present invention relates to a head-mounted display device.
2. Related Art
A head-mounted display device (a head mounted display (HMD)), which is a display device mounted on the head, is known. For example, the head-mounted display device generates image light, which represents an image, using a liquid crystal display and a light source and guides the generated image light to the eyes of a user using a projection optical system and a light guide plate to thereby cause the user to visually recognize a virtual image. As the head-mounted display device, there are two types, i.e., a transmission type with which the user can visually recognize an outside scene in addition to a virtual image and a non-transmission type with which the user cannot visually recognize the outside scene. As the head-mounted display device of the transmission type, there are an optical transmission type and a video transmission type.
JP-A-2012-165084 (Patent Literature 1) discloses a head-mounted display device that performs, when a user performs predetermined operation while visually recognizing a virtual image such as a content video, control for not irradiating light from a light source to enable the user to easily visually recognize an outside scene without causing the user to visually recognize a virtual image. JP-A-2011-91789 (Patent Literature 2) discloses a head-mounted display device that detects number-of-steps information during walking of a user and performs control of an image for causing the user to visually recognize the image as a virtual image according to the detected number-of-steps information. JP-A-2011-14082 (Patent Literature 3) discloses a device that causes, according to a motion of a user, the user to visually recognize an image representing information set in advance.
However, with the head-mounted display device disclosed in Patent Literature 1, when the user desires to visually recognize an outside scene while visually recognizing a video as a virtual image, the user can visually recognize the outside scene by performing a predetermined operation but cannot visually recognize the video that the user has been visually recognizing. Therefore, there is room of improvement in a method of causing the user to visually recognize the outside scene and the video. In the technique disclosed in Patent Literature 2, a video visually recognized by the user is controlled according to the number-of-steps information of the user. Therefore, an outside view or a video visually recognized by the user sometimes does not reflect an intention of the user. Consequently, there is room of improvement concerning the control of a video visually recognized by the user. In the technique disclosed in Patent Literature 3, the image representing the information set in advance is visually recognized by the user according to the motion of the user. However, the user sometimes cannot select, according to an intention of the user, the size and the like of the image to be visually recognized, for example, when the user desires to visually recognize the image in a larger size. Therefore, there is room of improvement in convenience for the user. Further, there is a demand that the user should visually recognize, with simpler operation, an image that reflects an intention of the user.